1. Field of the Invention
This invention relates to an original-feeding device capable of separating and feeding the uppermost original of a bundle of originals, and capable of separating and feeding the lowermost original of the bundle.
2. Description of the Related Art
In conventional original-feeding devices, originals are sequentially fed only either from the first page or the last page. In an ordinary original-copying operation, the copying operation starts, in most cases, from the last page in consideration of ease in processing of copying sheets.
Recently, copiers also having a facsimile function have been realized. In this kind of copiers, originals must be processed from the first page when the facsimile function operates. Accordingly, automatic original-feeding devices for such copiers have been proposed in which, when the copier performs a facsimile operation, processing starting from the first page (feeding of upper originals) is performed, and when the copier performs an ordinary original-copying operation, processing starting from the last page (feeding of lower originals) is performed.
However, in the above-described conventional automatic original-feeding devices capable of performing two kinds of original-feeding operations, i.e., processing starting from the first page and processsing starting from the last page, it is impossible to perform control of an original-feeding operation which allows a duplex mode of performing copying or facsimile transmission of an original having printed images on both surfaces thereof, or a 2-in-1 mode of copying two originals on one copying sheet or performing facsimile transmission of two originals without providing an interval between the two originals to provide a situation as if a single original were transmitted.
When, for example, obtaining a duplex copy from a simplex original, it is necessary to know whether the number of originals mounted on an original-mounting tray is even or odd when starting processing from the last page. On the other hand, when starting processing from the first page, it is unnecessary to know whether the number of originals mounted on an original-mounting tray is even or odd even when reading both surfaces of a simplex original. Hence, it is wasteful to detect whether the number of mounted originals is even or odd for the latter case.